Protozoa Extra Information Flashcards
Plasmodium babesia
Apicomplexa
intermediate host = mammals and birds (multiplies in blood)
Definitive host = arthropod (multiplies in gut –> glands)
Flagellates (4)
Giardia
Trichomonas
Trypanosoma
Leishmania
Amoebozoa (3)
Entanomoeba
Acanthamoeba
Hartmanella
Alveolates (3)
Cortical alveoli, flattened membrane-bound sacs
Apicomplexa
ciliates
dinoflagellates
Apicomplexa
Under alveolates, have apical complex for cell invasion
Plasmodium, Sporozoans, coccida, microsporida
Ciliates (2)
under alveolates
balantidium (GI)
Paramecium (non-pathogenic)
Dinoflagellates
Under alveolates
photosynthetic algae, kill marine organisms, secrete toxins (found in fish, shellfish)
Amoebic meningocephalitis
Clinical: Rapidly progressive, death 1 week
Patho: Free-living amoebas: Naegleria, Hartmanella, acanthomeoba infection from natural water swimming. Amoebas enter nose –> sinuses –> brain
Treatment: Amphoterecin and azoles
Acanthomeoba
keratitis: contact lens solution made with contaminated H2)
Neurological poisoning among laboratory workers
photosynthetic protozoa: dinofalgellates produce potetnt oxins, disease contracted by shellfish that ate toxins.
pfeisteria pscidida
Balantium Coli
Disease similar to histolytic (amebic dysentery)
- find organism in stool
- large trophozoites with kidney shaped nucleus
- cysts are large and round
Apicomplexa life cycle
Trophozytes –> multiple nuclear divisions without cytokinesis–> multinucleate SCHIZONTS –> schizogeny (cleavage) –> multiple uninucleate infective progeny released by lysis of host cell
Tachyzoites = fast dividing. Bradyzoites = slow dividing, Hypnozoites = semi-dormant
Forms with Sexual cyle:
Also produce macro gametocytes and micro gametocytes. In definitive host gametocytes –>meiosis–>haploid gametes –>fusion to form diploid zygote –>multiplies by schizogeny –> infectious for new intermediate hosts
Plasmodium Babesia
Intermediate host (asexual) = mammal or bird Definitive host (sexual) = arthropod vector - multiplies in gut spreads to salivary glands
Toxoplasma Sarcocystis
Intermediate host (asexual) = rodent or ungulate - multiplies in gut, encysts in tissue, humans are accidental host Definitive host (sexual) = carnivore - multiplies in gut shed in feces
Cryptosporidium Isospora
Humans both intermediate and definitive host. Sexual and asexual cycles in gut, spread by fecal/oral route
Mosquito cycle of plasmodium falciparum
gametocyte infectious to mosquito. they undergo meiosis to produce haploid gametes. Microgametocytes make flagella and motile gametes. In the gut these fertilize macro gametocytes to form zygotes (ookinetes) which invade the gut wall and for oocysts. Oocysts undergo sporogeny, producing multiple sporozoites which move to the mosquitos salivary glands.
Babesia microti
reservoir in dogs, livestock. vector: ticks
Malaria-like endemic in NJ.
Diagnosis: blood smear, ring forms (rarely) cruciform
Isospora belli
Fecal/oral, diarrhea, fever, abdominal pain. diagnosis by fecal smear
Cyclospora cayetanensis
Fecal/oral, outbreaks from contaminated fruit/vegetables. Diarrhea, occasionally severe enough for hospitalization. Diagnose by cysts in acid-fast
Sarcocystis
cycsts in raw/undercooked meat. Cycles between carnivores (intestinal form) and ungulates (muscle cysts). Encysts in muscle usually do not produce disease.
Diagnosis are serological.
Microsporidia Life Cycle
Infectious form is the spore. Inside spore wall, cytosol of microsporidian is continuous with lumen of a long coiled polar filament. When spore contacts host cell, filament everts and pierces host cell plasma membrane. osmotic flow of water into spore forces cytoplasm of parasite through polar filament and into cytosol of host cell, where it develops into a trophozoite and then a schizont. Mitotic and meiotic divisions form zygotes, infectious spores are formed and released via lysis.
Immune-compromised people are at risk
